VIEWS: 5 PAGES: 13 CATEGORY: Optics POSTED ON: 6/13/2010
FIELDthis invention relates to methods and apparatus useful in immunoassay of a fluid. In typical embodiments of the invention, light is directed to an optical sensor wherein the light is transmitted to a replaceable optical device that is responsiveto index of refraction in a sensing region thereof that is exposed to the fluid. One portion of the light is transmitted via a reference path to a first detector. Another portion of the light is transmitted via a sensing path that includes the sensingregion to another detector. A ratioing device receives an output from each detector and provides a signal responsive to the ratio of the outputs. The replaceable optical device typically comprises a pair of channel waveguides in directional couplingarrangement, or a pair of channel waveguides in an interferometer arrangement, or a ridge waveguide having a serpentine path.Typical embodiments of the invention comprise integrated optics devices for immunoassay of whole blood or other body fluids, typically including low cost, disposable sensors in channel waveguide configurations such as serpentine multimodewaveguides, single mode waveguides in coupler configurations, and single mode waveguides in interferometer configurations.BACKGROUNDThere is need for low cost, rapid, and accurate means for quantitative analysis of whole blood and other body fluids in medical diagnostics.Some of the methods representative of the current state of the art have been recently reviewed by Bluestein, et al, [Bluestein, B. I., Walczak, I. M., and Chen, S., "Fiber Optic Evanescent Wave Immunosensors for Medial Diagnostics" Tibtech, 8,161-168, June, 1990].Biosensors provide rapid response, real time monitoring of the sample/sensor interaction to produce an electronically quantified result. A biomolecular component of the sensor is used to recognize the analyte of interest. These recognitioncomponents include molecules such as antibodies, enzymes, lectins, hormones, DNA, and neuro-transmitter r
"Integrated Optical Directional-coupling Refractometer Apparatus - Patent 5173747"